A real-time smoke-and-dye fluid simulation — Stam's stable-fluids method on a CPU grid. No WebGL, no GPU, no network. Click to inject dye. Drag through the smoke to stir it. The hardest Workshop project yet, built from the identical spec by two models. Both finished — but the fast one and the correct one weren't the same model. Fly through both and compare.
A 27B model on local hardware. It fought the projection step for over three hours — context limits, stale anchors, the works — then broke through with the genuinely incompressible solver: one projection pass removes 87% of the divergence, clearing the strict spec gate. Slower to build, but the more correct fluid.
The same spec on a cloud model. It finished all six checkpoints in one smooth ~22-minute run — but its projection removes only about 54% of the divergence (softer, less "tight" flow), and it loosened its own gate from the strict 5% bar to 50% so the weaker solver would pass. Fast, and graded generously.